Favorite Epoxy/Resin Fillet Fairing gel coat combo

Discussion in 'Materials' started by Munson, Mar 25, 2021.

  1. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    The pulpit hangs over my dock and during a bad storm it takes a beating along with the dock, so I don’t think extending the pulpit will work.I was actually told by the fleet captain to cut the pulpit off.
     
  2. fallguy
    Joined: Dec 2016
    Posts: 4,634
    Likes: 824, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Your glass plan is wrong. Don't use csm or mat with epoxy.
     
  3. kapnD
    Joined: Jan 2003
    Posts: 848
    Likes: 132, Points: 43, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    Sounds like you’ve got bigger fish to fry anyway!
    I was meaning to extend it towards the stern, over the area you are talking about closing in.
     
    Munson likes this.
  4. missinginaction
    Joined: Aug 2007
    Posts: 1,040
    Likes: 218, Points: 63, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    Hi Munson,

    I'll follow along here. I'm glad I brought up the engineering as it's important. That said it's a bit beyond my area of expertise, without me doing considerable homework at least. Consider posting some additional information. Boat displacement, maybe make and model, things of that nature that will give people a little more information to go on. You might also consider posting in the "Fiberglass and Composite" section.

    This is certainly a "doable" project. It just depends on how much time, effort and money you want to sink into it. At least I could give you some ideas on the finishing aspects.

    MIA
     
    Munson likes this.
  5. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    It is a 1992 bayliner trophy 2359 4150 weight
     
    Last edited: Mar 27, 2021
  6. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    I believe it will withstand the pressure of the windlass.My anchor was once caught in an abandoned lobster pot In 50-60 feet of water in the Long Island sound.Although it took 2 men an hour worth of time I got my anchor back.The reason why I mention this is because the pulpit gave great flex and when we needed a break the cleat took a great deal of pressure.Although that is several inches forward of the box.I believe the box will withstand.
    One more thing I failed to mention is the “box” I plan to build will overhang over the existing topside about 2 1/2 inches (1/2 inch from bow pulpit)and will be carriage bolted down.
    Also what epoxy do you recommend,I was leaning towards West System or total boat because they are advertised the most on the Internet.West has the amine blush residue and total boat does not.
     
    Last edited: Mar 29, 2021
  7. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    The pulpit is actually lower (recessed) than the area I plan on mounting to,I think you are right it will be a lot more work.
     
    Last edited: Mar 28, 2021
  8. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    BF73EBAC-214C-44E2-BBBA-AF08CF11BE33.jpeg So use this stuff you suggested for taping inside corners 2-4 times then wrap the whole box with it also?If so how many times for the whole box.Is there a wait time between taping corners and laying glass.Is there too many layers of glass I can lay at one time?I also plan on using a Kreg jig with SS screws for reinforcement and rounding the edges with a router,is that ok?What kind of epoxy do you recommend?West system?fast or slow?
     
    Last edited: Mar 29, 2021
  9. missinginaction
    Joined: Aug 2007
    Posts: 1,040
    Likes: 218, Points: 63, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    Chopped strand mat is typically used to prevent print through (the weave showing) when laminating a hull. You don't need to use it on a box as it won't add any strength and will just soak up more resin, making it heavier but not stronger.

    As for resins, I'm not personally a fan of West. The reason? The 5:1 mix ratio. I've used a lot of 2:1 ratio epoxies with great results. My favorites are System Three and MAS. I agree with people who say that "penetrating" resins are a gimmick. There are epoxies like System Three Clear Coat and MAS Low Viscosity Resin that are 100% epoxy (they contain no thinning solvents) but are engineered to a lower viscosity.

    This time of year in New York State I tend to use fast or medium hardeners. It's not warm enough for the slow hardeners, yet.

    As for the cloth, I'd use a 6 oz or a 9 oz cloth and perhaps some 9 oz fiberglass tape building up the laminate. I'd suggest building the "box". Rounding over all of the sharp corners (fiberglass doesn't like going around sharp corners) then sealing the box with three coats of neat resin. After that cut and lay up your fiberglass. Layup the glass on both inside and outside the box for a strong assembly. You could also cut the box panels and cleats. Then fit everything together, dry. Once you're happy lay out the parts on a workbench, put some 1/4" wooden dowels under the parts and start sealing them.

    For a really strong box use as few fasteners as possible. The resin and glass will keep it together and strong. For example that photo of my flybridge that I sent you earlier has only 6 screws holding a cleat in place that the entire flybridge is built on. The entire bridge is tongue and groove construction glued together with System Three Resin. Very strong and no screws to allow water to leak in.

    If you haven't read it yet take a look at The Epoxy Book. You may find it helpful.

    Literature https://www.systemthree.com/pages/literature

    This may be confusing to you what with all the opinions but stay focused and stay patient. Working with glass and resin isn't rocket science but there is a learning curve. Be patient, you'll get there.

    MIA
     
    Munson likes this.
  10. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    MIA, do I need to tape the outside corners also?Can I tape and layer all at once or is that too ambitious?I compiled a list of steps I think I should be going through thanks to You, and others that have helped me in her along with YouTube and some other reads.Please let me know if this is overkill.It’s a combination of everyone’s inputs;
    Build Windlass box

    1a)Rough sand plywood

    2)Cut 3/4 Marine plywood and fit

    3)Clamp corners and pilot screw holes(kreg jig)

    4)Screw box together and route a 3/8 corner round.

    5)Cut length of tape (10.oz fiberglass)for inside corners and outside? Corners.

    6)Cut 10.oz Fiberglass layers for inside and outside

    7)Disassemble box,mix epoxy and lay down on areas where screw joints meet/screw box back together

    8)Make enough epoxy to coat entire box corners 2x

    9)when tacky mix filler and lay inside corners.

    10)Wet corners and lay in tape/wet over tape (2 layers)then roll out bubbles.

    11)wait time? Wet box and lay 6.oz Fiberglass covering inside and out 2-3 layers,also roll out bubbles.

    12)Wait till tacky and apply 2 additional layers of epoxy

    13)Wait 7 days to cure and remove amine blush with abrasive and water(depending on epoxy)

    14)Sand (what grit?)and fair glass if needed

    15)Apply primer/sand when dry

    16)Apply interlux perfection/Roll in one direction and brush in crossing direction

    17)Sand?
     
  11. missinginaction
    Joined: Aug 2007
    Posts: 1,040
    Likes: 218, Points: 63, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    A couple of things......

    This isn't a huge project. Even so you'll need some Colloidal Silica or better yet Cabosil to thicken your resin. You'll also need some Q-cells (these are lightweight micro balloons that sand easily) to make up a fairing compound. Read that Epoxy Book and you'll understand this.

    #4 If you can use a 1/2 inch round over bit so much the better.

    #5 No need to tape outside corners. Just cover the box with additional layers to build up the laminate.

    #7 Counter sink any screws that you use (304 stainless minimum, 316 preferred) then just fill the counter sink with epoxy and sand smooth. Just lay up your cloth right over the countersunk screws.

    #9 You can make fillets more easily using the "rubbing alcohol trick". Thickened resin has a tendency to stick to everything. It's difficult to get a smooth fillet. Once you've smoothed your fillet as best you can allow the resin some time to reach a plastic or semi-solid state. This state will last for a longer period of time with medium to even slow hardeners. While the resin is in this state wet a latex gloved finger with isopropyl rubbing alcohol. The alcohol will allow you to smooth the fillet and work it into corners and shape it without the glove sticking. You can also use wooden cleats on inside corners. Depending on the angles involved this can be a good option.

    #13 I've never waited a week before painting. Just follow the manufacturers guidance regarding cure times.

    #14 I sand with 120 grit unless I have a really tricky fillet then I get more aggressive (maybe 60 or 40 grit) and then recoat the fillet until I get it right.

    #15-16 Just follow the directions with the epoxy prime coat and the finish paint. If you use Perfection follow the instructions TO THE LETTER. I'd practice on a scrap piece, maybe make up a scrap piece coated with resin while you're making the box. I find that 3" rollers and disposable chip brushes work fine. You want a thin nap roller. Also keep in mind that with Epoxy Prime coat you'll need brushing/rolling thinner at 25%. You'll understand why when you open the can. For Perfection you'll thin more when it's cool and less when it's in the 80's or 90* but never more than the max that the manufacturer recommends, 10% I think it is. When you first try using Perfection, thinning can be tricky. If you think you want 10% try just a splash first and see how it rolls out. You can then add a bit more if necessary and "sneak up" to the best mix. If it's hot try Perfection with no thinner at all, you'll get a nice result. Pot life is pretty long with Perfection so you'll have time to play around with it. One more thing, with Perfection "less is more". It's a thin product that covers very well. Lay on 2-4 thin coats. If you try to go heavy it will run on you. Thin, thin , thin coats.

    These are the rollers I use. You can cut them with a hack saw and miter box to fit a three inch roller frame.
    https://www.amazon.com/Wooster-Brus...locphy=9004606&hvtargid=pla-511352533392&th=1

    Good Luck,

    MIA
     
    Munson and fallguy like this.
  12. fallguy
    Joined: Dec 2016
    Posts: 4,634
    Likes: 824, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Not really best way.

    Best way is to screw and bond.

    Inside tapes.

    remove screws, router edges

    screws and routers are a bad combination
     
  13. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    1)Ok so do not tape outside box,Will 3 full coverings on the outside suffice
    2)Do I tape the inside and cover or just tape the inside.
    3)Thank you for your time and knowledge I appreciate the help from you and everyone who added to the conversation.I had a few minutes of free time yesterday to read some of that book.I didn’t read all of it, just areas that pertain to the project.It’s a bit tough trying to crash course into a skill and art craft,learning methods, material and terms.I also live in New York and I am trying to time the weather with the project along with everything going on in every day life.I am pulling the trigger on the materials today.Thank You!!
     
  14. missinginaction
    Joined: Aug 2007
    Posts: 1,040
    Likes: 218, Points: 63, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    There are always different ways to do things fallguy. You're right about the screws.

    I was thinking that munson would route the edges before he assembled the box and then he could countersink the screws and bury them. Cleats on the inside. I'm with you on the screw removal though.

    Not to get off topic but a few years ago I built this folding platform for the generator that sits off the transom. I planed down some Philippine Mahogany to 1/2 inch and then laminated up a couple of layers. One layer was oriented 90* to the other. I used a few screws to hold it together as it cured and then removed them. Prettied it up, sanded and finished it and that was it. It's white so it doesn't get that hot in the sun. Well, one day I'm on the boat and I hear this "bang!". Turns out that the platform just overcame the strength of the resin and blew itself apart at the lamination. Not the whole platform but one corner of it shifted about 3/16". It's still functional and I just sanded off part of it and mixed up some resin/filler and redid the edge that shifted. It's rectangular and near as I can figure the long pieces of wood expanded more than the epoxy could handle and they separated from the shorter pieces.
     

  15. Munson
    Joined: Mar 2021
    Posts: 49
    Likes: 2, Points: 8
    Location: New York

    Munson Junior Member

    What does cleats on the inside mean?inside corner trim?
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.